Gas-compressing pump



(No Model.)

1). BOYLE.

GAS OOMPRESSING PUMP.

No. 319,446. Patented June 9, 1885.

INVENTUR BY Wm W Fig. 6. WITNESSES:

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DAVID BOYLE, on onicnoo, inmnors.

GAS -COPRESSBNG PUMP.

$PECIFICATION forming part of Letters Patent No. 319,446, dated June 9, 1885.

Application filed October 6, 1884. (No model.) 7

To all whom it may concern:

Be it known that I, DAVID BOYLE, a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Gas-Compressing Pumps, of which the following is hereby declared to be a full, clear, and exact description, sufficient to enable others skilled in the art to make and use the same.

My invention relates to gas-compressing pumps, such as are used in condensing the liquefiable gas or vapor employed in refrigerating or ice machines. Double-actin g pumps were formerly used for this purpose; but they wereliable to serious loss of gas at the stuffingboX of the piston-rod, owing to the box being subjected at each alternate stroke of the piston to the high pressure required to force the gas into the condenser, in the case of ammonia this pressure being from one hundred and twenty-five to two hundred and fifty pounds on the square inch. It was to overcome this difficulty that in the year 1875 I introduced the single-acting pump, to the improvement of which my present invention particularly relates. In single-acting pumps the gas-supply from the refrigerating or expansion coils is admitted into and discharged from one and the same end of the pump-cylinder, which may be termed the condensingend. Into the opposite or non-condensing end of the pumpcylinder, back of the piston-head, opens a supplemental conduit or supply-pipe, which is in communication with the main conduit that leads from the refrigerating-coils to the condensing end of the cylinder. The noncondensing end of the pump-cylinder, being thus in free communication with the main gasconduit, is subjected only to the low and uniform pressure of the refrigerating-coils, for the reason that at each return-stroke of the piston the gas behind the piston-head escapes freely back into the supplemental and main conduits without increasing the pressure upon the stuffing-box. Should the supply of the refrigerating-liquid be in quantity greater than can be converted into gas by the heat absorbed in the expansion-coils, the excess of liquid comes over from the coils to the pump, together with the gas, and tends constantly to abstract the heat from the surrounding parts. This tendency, so far as concerns the condensing end of the cylinder, is more than neutralized by the heat developed under compression; but at the back of the piston-head there is no such modifying influence, and the liquid coming intothis end of the cylinder through the supplemental conduit passes at once into gas and renders the piston-rod exposed thereto intensely cold, thereby causing this rod to contract sensibly in diameter, so that the packing in the stuffing-box is no longer tight-fitting; hence under such condition a portion of the valuable gas is forced past the defective packing into the air at each return-stroke of the piston-head.

To remedy this objection is the main purpose of my invention; and to this end my invention consists,primari1y,in placing at some In the accompanying drawings, Figure 1 is a view in vertical longitudinal section, parts being shown inelevation. Fig. 2 is a View in cross-section on line a; a: of Fig. 1. view in elevation,on a reduced scale, of a modified form of apparatus for trapping the liquid, to prevent its passage into the non-condensing end of the cylinder.

The pump which I employ is of any ordinary single-acting type, the cylinder A havin g at its condensing end the usual two-chambered head, a, in which are set the inlet-valve 1 and outlet-valve 2. The solid piston-head B is reciprocated by the piston-rod b, working through the stufiingbox 3 in the bottom head, a, of the cylinder. The main supply- .pipe 0 discharges into the chamber a of the head a, while the exit-pipe d, to convey the compressed gas from the pump, opens from the chamber a of the head. Between the pump and the expansion-coils the main supply pipe, instead of being continuous, as here- .85 Fig. 3 is a 1 main cylinder, extends in front-of the orifice 6, and serves to prevent the current of cold gas as it enters from impinging directly upon the piston-rod, and thereby chilling it, and as Well prevents any injury of the rod by mechanical impurities sustained by the incoming current of gas. It is obvious, of course, that instead of forming the shield of the shape shown and attaching it to the cylinder directly in front of the orifice c it may be made of a other suitable shape, and may be-held in any proper position for protecting the piston-rod from the direct force of the gas current. Pipes, as at c and 6, similar to the section '0 of the main supply-pipe and to supplemental conduit 6, respectively, may lead ,to a second pump (not shown) and be connected therewith in like manner as pipes c and e are joined to pump-cylinder A.

In order to effect the proper lubrication of the pump-cylinder, I place the orifice e of the supplemental conduit 0 a sufficient distance above the cylinder-head a to form at the end of the cylinder a receptacle for oil. Within the oil-receptacle thus formed dips the circular oil-carrier F, that is shown as sustained by the straps f from the collar f on the piston-rod, although it will be readily understood that it may be sustained from the piston head or rod in other suitable manner. This oilcarrier is preferably formed trough-sh aped,

with its outer wall perforated near the bottom, so that as it rises with the piston it will lift sufficient oil to thoroughly lubricate the cylinder. The carrier F is formed with an open space, as seen in Fig. 2, to permit it to freely pass the shield 6 From the foregoing description the opera- I tion of the parts is manifest. The mixed gas and liquid coming by pipe 0 from the expansion-coils dischargesinto the trap O; the liquid falls on the bottom thereof, while the lighter gas rises to the top of the trap, and is the only part which can escape by supplemental conduit 6 to the back of the piston-head in cylinder A. The liquid, together with the gas, freely discharges from the drum 0 by main supply-pipe 0 into chamber a", and during end of the cylinder.

. mental conduit is effected in a modified manner. I

.Inthis arrangement the pipes. 0. and c constitutea continuous conduit leadinglfrom the refrigerating-coils to the condensing end of the cylinder. The supplemental conduit 0 rises above the main conduit 0, and is joined to the ,IIIRPBILIQQG, thereof. By thus connecting the supplemental conduit to the main conduit it will be readily seen that the liquid will be effectually separated from the gas entering the non-condensing end of the cylinder.

- Instead of arranging the supplemental conduit to connect with the main conduit in the position shown, it may be connected in any other suitable manner which will serve to effect the desired separation of the liquid from thegas. a It is plain from the construction and relation of the parts defined that since it is substantially the dry gas alone which enters the cylinder at the back of the piston-head the piston-rod is no longer subjected to the extremes of cold heretofore encountered, no ma terial contraction thereof occurs, and the packing in the stuffing-box snugly encompasses the same to prevent the wasteful escape of the gas.

I do not wish to be understood as confining my improvements to the precise details of (onstruction or relative arrangement of parts hereinbefore described, since these may be modified by the skill of the mechanic without departing in the least from the spirit of my invention. Thus, for example, the trap or equivalent means for separating the liquid from the gas entering the non-condensing end of the pump may be placed at any convenient position between the refrigerating-coils and such part of the pump.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination, with a single-acting gas-compressing pump having an inductionconduit for delivering gas from the evaporating-coils into the condensing end of the pump, and an induction-conduit for delivering gas from the evaporating-coils into the non-condensing end of the pump, of a trap between the evaporating-coils and the pump, whereby the gas supplied to the non-condensing end of the pump shall be freed from liquid, substantially as described.

2. The combination, with the single-acting compression-pump cylinder A, having inlet and outlet valves at the condensing end thereof, of the main-supply pipe, consisting of the divided sections a and c, the interposed trap G, and the supplemental conduit 6, leading from the top of said trap to an orifice, e, in

the pump-cylinder Aback of the piston-head,

substantially as described. v

3. The combination, with a gas-compressing pump having induction-pipes for delivering gas to the condensing and non-condensing ends of the pump, of a shield for protecting the piston-rod of the pump, substantially as described.

4.. The combination, with a vertically-arat its non-condensing end and the piston head and rod, of the trough-shaped 0i1-carrier connected with the piston-rod, and cut away at a point in front of said gas-delivery orifice, substantially as described.

DAVID BOYLE.

Witnesses (3120. P. FISHER, J 12, FREDERICK S. BAKER. 

